1. Filed of the Invention
The present invention relates to a wheel cleaning apparatus for a wheelchair capable of automatically cleaning the wheels while a person is getting on the wheelchair.
2. Description of the Related Art
At an entrance of a hospital, a nursing institution, or the like, it is indispensable to remove dirt such as disease-causing germs or mud attached to the wheels of a wheelchair in order to prevent the dirt from being brought into the hospital or the like. A wheel cleaning apparatus for a wheelchair is known which comprises first and second receiving rollers (parallel rollers) which can rotate while receiving the wheels, and which are almost parallel and arranged facing to each other, roller driving means for driving at least one of the first and second receiving rollers to rotate and a cleaning brush contacting the wheel which rotates on the receiving rollers in accordance with the rotation of the at least one receiving roller.
A wheelchair generally has rear wheels with large diameters (50-60 cm) and front wheels with small diameters (10-20 cm), which are free to change their directions in the right or in the left to change the course of the wheelchair. Also, in general, a wheel cleaning apparatus for a wheelchair is a floor-type apparatus, which is appropriately placed on the floor. Therefore, the positions of the first and second receiving rollers are higher than the floor surface and, accordingly, an upward slope plate and a downward slope plate must be provided to bridge the floor surface and the first and second receiving rollers. When the wheels are to be cleaned, a helper pushes the wheelchair to move it while a person is riding on the wheelchair. By this pushing of the wheelchair, the front wheels are pushed up on the upward slope plate and extend over the first and second receiving rollers. In this state, the front wheels are cleaned. During such cleaning of the front wheels, the rear wheels are on the upward slope plate. After cleaning the front wheels, the helper pushes the rear wheels up on the upward slope plate to place them over the first and second receiving rollers, and then the rear wheels are cleaned. During such cleaning of the rear wheels, the front wheels are on the downward slope plate. After cleaning the rear wheels, the wheelchair is slowly lowered from the downward slope plate to the floor.
In the above-mentioned wheel cleaning apparatus for a wheelchair, however, there are the following problems.
The interval between the first and second receiving rollers must be set to a sufficiently short distance so that the front wheels do not fall downward from the gap between the first and second receiving rollers. However, there are various diameters of the front wheels, from 10 cm to 20 cm depending on the type of the wheelchair. If the interval is set for a front wheel having the minimum diameter when it is employed as a standard front wheel, the rear wheels with large diameters tend to slip off the first and second receiving rollers against the helper""s will. This is because, when a rear wheel having the large diameter is to be cleaned, the angle from the contact points between the rear wheel and the first and second rollers to the central axis of the rear wheel is small because of the large diameter. Therefore, the stability of the rear wheels when driven to rotate tends to be bad. On the other hand, if the interval between the rollers is set to large to avoid the wheels slipping off, the cleaning of the minimum diameter front wheels of a wheelchair is impossible. When the front wheels have medium diameters, the front wheels drop in the gap between the first and second receiving rollers when the front wheels are placed on the first and second receiving rollers by pushing the wheelchair to advance and climb the slope. Therefore, even when the wheelchair is strongly pushed after cleaning the front wheels, the roller at the escaping side obstructs the front wheels. It is hard to push over this. It is possible to push the rear wheels while raising the front wheels, however, this forces the helper to do something dangerous. Accordingly, it is very difficult to separate the front wheels from the gap. Therefore, the wheel cleaning apparatus of the rotary parallel roller type is not practical.
Second, in a wheel cleaning apparatus in which a cleaning brush is used to brush off dirt from the rotating wheels, only the dirt attached to the wheels is scraped off. Microscope objects such as bacteria cannot be removed. Further, the dust is scattered around, so the sanitary environment in the institution is damaged. Still further, there is a problem in that the cleaning brush itself must be periodically cleaned.
In view of the above-mentioned problems, a first object of the present invention is to provide a wheel cleaning apparatus for a wheelchair, in which slipping of the rear wheels during cleaning can be prevented, the front wheels can be easily separated from the gap between the receiving rollers, and the load on the helper can be reduced.
A second object of the present invention is to provide a wheel cleaning apparatus for a wheelchair, in which it is possible to automatically wash and wipe the wheels without forcing the helper to do cleaning work and it is possible to obtain a high reliability in removing the dirt from the wheels.
To attain the above-mentioned first object, the specific feature of the wheel cleaning apparatus for a wheelchair resides in that the parallel rollers are supported to be able to rock. That is, the wheel cleaning apparatus for a wheelchair according to the first aspect of the present invention comprises a roller-assembly frame including first and second receiving rollers which can rotate while receiving at least one wheel of the wheelchair, the first and second receiving rollers being almost parallel and arranged facing to each other, roller driving means driving the rotation of at least one of the first and second receiving rollers, cleaning means cleaning the at least one wheel driven to rotate on the first and second receiving rollers, a rocking and supporting mechanism supporting the roller-assembly frame so that the roller-assembly mechanism can rock in a positive and negative directions with respect to a central axis of the rocking, and energizing means energizing the roller-assembly frame in a direction so that the second receiving roller springs up from the first receiving roller.
It should be noted that, in this first aspect of the present invention, since the wheel cleaning apparatus for a wheelchair has a single pair of parallel rollers, the length of each of the parallel rollers must of course be larger than the distance between right and left wheels when the two rear wheels or two front wheels are to be placed in the roller-assembly frame and cleaned simultaneously.
The first and second receiving rollers may receive a single right or left wheel when each of the parallel rollers has a short length.
In the following, it is assumed that there is a single pair of parallel rollers receiving a single wheel.
When the parallel rollers do not receive the wheel, i.e., under an almost no load condition, the energizing means energizes the second receiving roller to spring up from the first receiving roller so that the roller-assembly frame is tilted. Therefore, in a front wheel cleaning stage, by placing the front wheel of the wheelchair from the first receiving roller, which is in a pressed down state, the placement operation becomes easy. At that time, since the front wheel contacts the sprung up second receiving roller, the second receiving roller functions as a wheel stopper. When the front wheel contacts the sprung up second receiving roller, the placement point is moved so that the roller-assembly frame begins to rock in a seesaw movement against the energizing force in a direction to push down the second receiving roller. As a result, the roller-assembly frame becomes stable between the loading force and the energizing force so that the front wheels can be cleaned. After cleaning the front wheels, if the wheelchair is further moved in the front direction, the load on the second receiving roller is increased so that the second receiving roller is pushed down to reduce the step barrier, and in contrast, the first receiving roller is sprung up so that the front wheels are pushed to the front direction by the first receiving roller, resulting in that it becomes easy to separate the front wheels from the parallel rollers. The pushing force by the helper to the wheelchair reduces the step barrier for the front wheels and at the same time is converted to a pushing force from behind. Therefore, even when the interval between the parallel rollers is expanded, the front wheels can easily be separated from the parallel rollers. Further, the rear wheels can be effectively prevented from slipping off.
It should be noted that, after the front wheels are separated from the receiving rollers, the profile of the roller-assembly frame returns back to the initial tilt profile in which the first receiving roller side is pushed down.
As this energizing means, it may be possible to employ a tensional wire connected between the roller-assembly frame and a dead weight body. However, it is preferable to employ elastic means such as a spring of, for example, a torsion spring or a coil spring because, in this case, it is possible to make the apparatus to have a small size and to reduce the weight, and in addition, when the apparatus loads the front wheel, an elastic reaction force is generated in accordance with the pushed-down length of the second receiving roller so that the function to stop the wheels by the second receiving roller is improved, resulting in that the positioning of the front wheels can be instantaneously stabled.
In principle, the central axis of rocking of the roller-assembly frame may be a point dividing externally of the central axes of the shafts of both rollers, however, it is desirable that the central axis of rocking is at a point dividing internally of the central axes of the shafts of both rollers. Further, it is desirable that a shaft body arranged between both rollers realizes the central axis of rocking. This not only decreases the space occupied by the apparatus but also expand the range of the rocking angle so that the wheel stopping function and the function to push from behind after escaping are improved. Still further, since the shaft body is arranged between both rollers, the front wheels do not fall into the gap between the rollers even when the diameter of the front wheel is the minimum, and therefore, various types of wheelchairs can be applied to this apparatus for cleaning the wheels. Still further, a tiptoe of the helper is prevented from being fallen into the gap between the both rollers.
During cleaning of the front wheels, since all of the loads are not applied on the parallel rollers, and in addition, since the diameter of the front wheel is small, the front wheels are driven to rotate in a stable state. During cleaning of the rear wheels, however, almost all loads of the wheelchair are applied to the parallel rollers. Therefore, the roller-assembly frame rocks to oscillate more or less when a person to be helped moves to move the center of gravity of the wheelchair, resulting in that the stability is deteriorated.
To avoid the above problem, there is provided, in the outside of the roller-assembly frame, a third receiving roller as a subsidiary roller. The third receiving roller can rotate while receiving wheels of the wheelchair. The third receiving roller is almost parallel to the first receiving roller and arranged adjacent to the first receiving roller. It is desirable that the central axis of the rotation of the third receiving roller is at a position higher than the central axis of the rocking. When the real wheels are in contact the parallel rollers of the roller-assembly frame, the lower side arcs of the rear wheels having large diameters come to closely contact the parallel rollers which are in the rocking motion, so that the lower-side arcs are supported at the three points by the three rollers, resulting in that the stability during the cleaning of the front wheels is ensured.
When the third receiving roller is provided, it is desirable that the roller-assembly frame comprises a fall preventing body placed in a narrow gap between the first receiving roller and the third receiving roller, for preventing the wheels from being fallen into the narrow gap. The fall preventing body appears or disappears depending on the rocking movement of the roller-assembly frame so as to prevent the front wheels having the minimum diameter from falling, and the strength of the roller-assembly frame itself can be increased.
To attain the above-mentioned second object, there is provided, according to the present invention, a wheel cleaning apparatus for a wheelchair, wherein at least one of the first and second receiving rollers comprises a tube shaped body made of water-absorbing material and having an elastic contraction characteristic, the tube shaped body being fitted on the outer periphery of a rotary shaft portion, the cleaning means comprises the tube shaped body and washing liquid putting means for wetting the lower side of the tube.
Consider the wheel, which is in contact with the parallel rollers by pressure so as to be driven to rotate. At the side of the first receiving roller, the washing liquid from the washing liquid putting means wets the lower side of the first receiving roller. After the lower side of the water-absorbing material absorbs the washing liquid such as liquid medicine to be swelled, the liquid-absorbing swelling part rotates to be in contact by pressure, at its upper portion, with the lower end portion of the wheel so that the liquid-absorbing swelling portion is pressed to contract. During the contraction, the liquid in the upper contraction portion is squeezed out to continuously form a liquid pool (liquid cut portion) in a narrow gap between the tube shaped body and the wheel at the contact-starting end side, By this, the wheel is driven to rotate while the grounding side surface of the wheel is relatively being soaked in the liquid pool. Therefore, the grounding side surface of the wheel is continuously met with the nozzle-type washing. Thus, the dirt or the like on the grounding-side surface of the wheel can be washed away. Accordingly, since the wheel can be cleaned automatically, uniformly and with a high washing power, the dirt is not scattered as well as micro objects can be removed.
The amount of the held liquid in the liquid pool is determined by the ratio between the diameters of the receiving roller and the wheel, the rotating speed, the surface tension of the liquid, etc. The washing liquid squeezed out from the upper contracted portion is dammed up by the said upper contracted portion so that almost no washing liquid is transmitted to the narrow gap at the contact-ending side between the first receiving roller and the wheel. When the liquid-absorbing swelling portion has passed the position where the pressure between the first receiving roller and the wheel is the maximum pressure, the water-absorbing material itself recovers its shape by the elastic contraction characteristic to expand. Therefore, between the position of the maximum pressure and the contacting-end edge, the liquid on the wet layer on the grounding-side surface of the wheel is absorbed and wiped by the expanded absorbing material. Thus, not only the nozzle-type washing function, but also the wiping function of the wet layer can be expected. Further, since the tube shaped body itself is washed by the washing liquid, it can be always kept clean so that it is not necessary to remove dirt from the tube shaped body which is cleaning means.
As the tube shaped body functioning as a washing tube, it has the outer perimeter made of water-absorbing material having elastic contraction characteristic. The water-absorbing material having the elastic contraction characteristic can be made of elastic extensible material of porous material such as sponge, gigging having micro gaps through which the capillary phenomena can be seen, or fiber or nonwoven fabric cloth material such as felt. It may also be possible to employ material having water absorbing and water holding property, and which may be subjected to elastic deformation.
It is desirable that the tube shaped body has in its internal periphery a core tube capable of circumferentially sliding on the rotary shaft portion. By this construction, when the water-absorbing material has been worn, only the water-absorbing material can be pulled out from the core tube to exchange. Therefore, the running costs can be reduced in comparison to the case when the receiving roller as a whole is exchanged. Further, the core tube is made in such a way that when a restricting force is applied to the core tube, the core tube is slipped with respect to the rotary shaft portion so that the core tube does not rotate together with the rotary shaft portion. By this construction, when a hand or a leg touches with the washing tube, the tube shaped body stops its rotation. Therefore, accidents such as clothes are caught by the rollers can be prevented so that the safety is ensured. Preferably, when the apparatus does not load the wheels, the tube shaped body does not rotate even when the rotary shaft portion is rotating. To this end, the core tube is preferably made of hard material with low friction. By this construction, when the rotary shaft portion is started to rotate when the apparatus is loading the wheels, the liquid such as liquid medicine is not scattered.
It is desirable that the washing liquid putting means is a liquid pooling vessel for soaking the lower side of the tube shaped body in the washing liquid.
To make the core tube to be able to circumferentially slide on the rotary shaft portion, it may be possible to insert ball bearings in the gap between the core tube and the rotary shaft portion or to fill up with lubricant liquid such as grease. However, it is not desired that grease or the like is soaked in the liquid pooling vessel. Therefore, as the simplest construction, the core tube is simply fitted to the outside of the rotary shaft portion under a clearance fit condition.
Further, it is desirable that the tube shaped body is a circumscribed-type tube shaped body having a core tube the lower arc side of which remains an idle gap and the upper arc side of which contacts with the rotary shaft portion. By intentionally providing the idle gap larger than a fitting tolerance between the rotary shaft portion and the core tube So as to limit the contacting area between them, a multi-contact friction wheelchair is realized in which the core tube has a limited friction contact portion at the upper arc side of the rotary shaft portion. Therefore, when the parallel rollers are not loading the wheels, the rotary friction force is not generated even when the rotary shaft portion is rotating so that the core tube does not rotate, and in contrast, when the tube shaped body is rotating while the parallel rollers are loading the wheels, if a hand or a leg touches with the tube shaped body to apply a restriction force to the tube shaped body, the rotation of the tube shaped body will stop due to a torque limiter function.
In particular, when the internal diameter of the core tube of the tube shaped body is considerably larger than the outer diameter of the rotary shaft portion, the central axis of rotation of the core tube is lower than the central axis of rotation of the rotary shaft portion. Therefore, the depth of the liquid pooling vessel, in which the lower side of the tube shaped body is soaked, can be made to be sufficiently long in such a degree as the distance in which the rotary shaft portion and the liquid pooling vessel do not interact to each other. As a result, the amount of the pooled liquid medicine, which is expendable supplies, can be made sufficient so that the bother in pouring and adding the liquid can be reduced. Still further, when the rotary shaft portion rotates while gravels are being caught at the upper contacting position between the rotary shaft portion and the core tube, the core tube may be spoiled by impulse kill due to friction or the like if the above-mentioned idle gap is not present. However, since there is the idle gap at the lower end portion, the washing liquid flows into the idle gap so that the attached gravels are washed away. Thus, the tube shaped body can be prevented from being spoiled.
In the above-described construction, at least one of the parallel rollers comprises a tube shaped body made of water-absorbing material and having an elastic contraction characteristic. Alternatively, each of the first to the third receiving rollers may have a construction to have a tube shaped body fitted on the outer periphery of a rotary shaft portion, and may be made of water-absorbing material having an elastic contraction characteristic. In this case, the cleaning means is constructed by the tube shaped body and washing liquid putting means for wetting the lower side of the tube shaped bodies of the first and second receiving rollers. The tube shaped bodies of the first and second receiving rollers each has the function as the washing tube as mentioned before, so that the washing effect can be improved by double washing. Further, the third receiving roller can wipe the water attached to the wheels so that it functions as a wiping tube. As a result, the washing time can be shortened.
In the above case also, it is desirable that each of the tube shaped bodies has in its internal periphery a core tube capable of circumferentially sliding on the rotary shaft portion. Further, it is desirable that each of the tube shaped bodies is a circumscribed-type tube shaped body having a core tube the lower arc side of which remains an idle gap and the upper arc side of which contacts with said rotary shaft portion.
When the tube shaped bodies of the first and second receiving rollers function as washing tube S, a common liquid pooling vessel may be provided to soak the lower sides of the tube shaped bodies of both rollers, however, if the common liquid pooling vessel is employed, there will be the following disadvantage. That is, during washing of the rear wheels, the first receiving roller is in a state of pushed down while the second receiving roller is in a state of sprung up. Therefore, when the washing liquid is exhausted so that the liquid surface of the liquid pooling vessel is lowered, the lower side of the tube shaped body of the second receiving roller is not soaked in the washing liquid, resulting in that the tube shaped body of the second receiving roller does not function as the washing tube.
To avoid the above disadvantage, it is desirable that the liquid putting means separately comprises a first liquid pooling vessel for soaking the lower side of the tube shaped body of the first receiving roller in the washing liquid and a second liquid pooling vessel for soaking the lower side of the tube shaped body of the second receiving roller in the washing liquid. By this construction, since the washing liquid in the second liquid pooling vessel is consumed only for the tube shaped body of the second receiving roller, the washing function of both tube shaped bodies can be continued for a long time regardless of the level of the liquid surface of the first liquid pooling vessel, resulting in that the bother in pouring and adding the washing liquid can be reduced.
Here, it is desirable that the second liquid pooling vessel is in the first liquid pooling vessel, and the upper edge of a vessel wall, in the vessel walls of the second liquid pooling vessel, at the side of the first receiving roller, is close to or in contact with the moving-upward outer surface of the tube shaped body of the first receiving roller. By this construction, the washing liquid is drawn by the absorbing and swelling the liquid by the water absorbing material on the moving-upward outer surface of the tube shaped body of the first receiving roller, and then is discharged to the liquid puddle. Then the liquid falls down along the moving-upward outer surface to be collected in the first liquid pooling vessel. Since the upper end of the vessel wall of the second liquid pooling vessel is close to or in contact with the moving-upward outer surface of the tube shaped body of the first receiving roller, the falling down washing liquid at the upper end is branched in accordance with the degree of the closeness or the contact. Then the second liquid pooling vessel receives the branched liquid. Thus, the washing liquid in the first liquid pooling vessel is transported to the second liquid pooling vessel by the tube shaped body of the first receiving roller. Further, when the transporting function is energetic, the second liquid pooling vessel overflows so that the overflowed liquid is returned back to the first liquid pooling vessel. Accordingly, by this circulating system of the washing liquid, once the first liquid pooling vessel is filled with the washing liquid, double washings can be continued until all of the washing liquid is consumed. Therefore, the bother in pouring and adding the washing liquid can be reduced, and the time necessary to wash the wheels can be shortened.
The first liquid pooling vessel has a function to receive the overflowed liquid from the second liquid pooling vessel. Therefore, generally a space, which covers three rollers, is needed. To avoid the interference with the rotary shaft portion or the like, the upper edge of the vessel wall cannot be so high for the purpose to increase the amount of the washing liquid. However, since the plane of the second liquid pooling vessel can be limited to the place under the second receiving roller, the upper edge of the vessel wall of the second liquid pooling vessel can be made to be higher than the upper edge of the vessel wall of the first liquid pooling vessel. In this case, the amount of the washing liquid as a whole can be increased so that the bother in pouring and adding the washing liquid can be further reduced.
Next, according to the second aspect of the present invention, there is provided a wheel cleaning apparatus for a wheelchair, comprising a pair of left and right roller-assembly frames. That is, to attain the above-mentioned first object, the apparatus comprises left and right roller-assembly frames each including first and second receiving rollers. In each roller-assembly frame, the first and second receiving rollers are able to rotate while receiving at least one wheel of the wheelchair. The first and second receiving rollers are almost parallel and arranged facing to each other. The apparatus further comprises roller driving means synchronously driving the rotation of at least one of the first and second receiving rollers in one of said roller-assembly frames and at least one of the first and second receiving rollers in the other one of said roller-assembly frames. The receiving rollers are driven synchronously to each other. Each of the roller-assembly frames still further comprises cleaning means cleaning the at least one wheel which is being driven to rotate on the first and second receiving rollers. Each of the roller-assembly frames still further comprises a rocking and supporting mechanism supporting the roller-assembly frame so that the roller assembling and supporting mechanism can rock in positive and negative directions with respect to a central axis of the rocking. Each of the roller-assembly frames still further comprises energizing means energizing the roller-assembly frame in a direction to spring up the second receiving roller from the first receiving roller in each of the roller-assembly frames.
By this construction also, both wheels can be cleaned simultaneously. In addition, as mentioned before, even when the interval between both wheels is set to expand, the front wheels can be easily from the apparatus. Further, the rear wheels can be effectively prevented from slipping off.
In this second aspect, because of the same reason as above, it is desirable that the energizing means is elastic means. The central axis of the rocking may be realized by a shaft body arranged in a narrow gap between the first and second receiving rollers, however, preferably, the central axis is realized by a shaft tube because a power-transmission shaft can penetrate through the shaft tube of the central axis of rocking. By this construction, the power can be transmitted to the intermediate area in the left and right roller-assembly frames without interfering to the rocking area of the left and right roller-assembly frames.
In the above construction in which the power transmission shaft is penetrated through the shaft tube, a first rotary shaft of the first receiving roller in the right roller-assembly frame and a first rotary shaft of the first receiving roller in the left roller-assembly frame are on the same axis through a first junction shaft; a second rotary shaft of the second receiving roller in the right roller-assembly frame and a second rotary shaft of the second receiving roller in the left roller-assembly frame are on the same axis through a second junction shaft; and the apparatus further comprises a power distributing mechanism for distributing and transmitting a power from the power transmission shaft to the first junction shaft and the second junction shaft. By this construction, since the power distributing mechanism is arranged in the intermediate of the left and right roller-assembly frames, the driving system can be simplified. Further, since the left and right rotary shafts can be driven at the center, a delay due to torsion of the rotary shaft does not appear so that the synchronicity of the left and right rotations is stabilized.
As the power distributing mechanism, it may be possible to employ the construction having a first winding and hanging mechanism transmitting the power from the power transmitting shaft to either one of the junction shafts, and a second winding and hanging mechanism transmitting the power from the one of the junction shafts to the other one of the junction shafts such as a roller chain. By this construction, since there is provided the second winding and hanging mechanism for winding and hanging the chain from the one of the junction shafts to the other one of the junction shafts, the synchronicity of the left and right rotations is stabilized in comparison with the case where the chains are separately wound and hanged from the power transmission shaft to the one junction shaft and to the other junction shaft.
Further, each of the roller-assembly frames is desired to comprise a bearing portion bearing the first and second rotary shafts in such a way as to be able to freely rotate and to be able to move to be tilted, the connecting edge portion of each of the first rotary shaft and the first junction shaft being a mutual inserting-type edge, and a hand touching sleeve fitted on the each connecting edge portion being fixed by fixing means in such a way that it can be attached or removed. By releasing the fixing means and by sliding the hand touching sleeve in a direction toward the junction shaft, the rotary shaft can be moved to tilt by using the bearing portion as its fulcrum. Therefore, the receiving roller can be drawn from the rotary shaft so that the bother in the maintenance and exchange of the receiving roller can be reduced. As the mutual inserting-type edges, a female end portion having an expanding slit and a male end portion having an inserting piece, or end portions having half cylindrical shapes to each other may be employed. As fixing means, a setscrew or a spring to set by pressure may be employed.
Similar to the first aspect of the present invention, in the outside of each of the roller-assembly frames, the apparatus comprises a third receiving. The third receiving roller can rotate while receiving at least one wheel of the wheelchair. The third receiving roller is almost parallel to the first receiving roller and arranged adjacent to the first receiving roller. It is desirable that the central axis of the rotation of the third receiving roller is at a position higher than the central axis of the rocking. Further, it is desirable that each roller-assembly frame comprises a fall preventing body placed in a narrow gap between the first receiving roller and the third receiving roller, for preventing the wheels from being fallen into the narrow gap.
According to the second aspect of the present invention, at least one of the first and second receiving rollers in each roller-assembly frame comprises a tube shaped body made of water-absorbing material and having an elastic contraction characteristic, the tube shaped body being fitted on the outer periphery of a rotary shaft portion, the cleaning means comprises the tube shaped body and washing liquid putting means for wetting the lower side of the tube shaped body.
In this construction also, the tube shaped body has in its internal periphery a core tube capable of circumferentially sliding on the rotary shaft portion. It is desirable that the tube shaped body is a circumscribed-type tube shaped body having a core tube the lower arc side of which remains an idle gap and the upper arc side of which contacts with said rotary shaft portion. As the liquid putting means, a liquid pooling vessel for soaking the lower side of the tube shaped body in the washing liquid can be employed. The tube shaped body is a circumscribed-type tube shaped body having a core tube the lower arc side of which remain an idle gap and the upper arc side of which contacts with the rotary shaft portion.
Further, each of the receiving rollers may comprise a tube shaped body made of water-absorbing material and having an elastic contraction characteristic, the tube shaped body being fitted on the outer periphery of a rotary shaft portion. The cleaning means may comprise the tube shaped bodies and washing liquid putting means for wetting the lower side of the tube shaped bodies of the first and second receiving rollers in the each roller-assembly frame. Each tube shaped body has in its internal periphery a core tube capable of circumferentially sliding on the rotary shaft portion, and the tube shaped body is a circumscribed-type tube shaped body having a core tube the lower arc side of which remains an idle gap and the upper arc side of which contacts with the rotary shaft portion.
When the washing liquid putting means comprises a first liquid pooling vessel for soaking the lower side of the tube shaped body of the first receiving roller in the washing liquid, and a second liquid pooling vessel for soaking the lower side of the tube shaped body of the second receiving roller in the washing liquid, it is desirable that the second liquid pooling vessel is in the first liquid pooling vessel, the upper edge of a vessel wall, in the vessel walls of the second liquid pooling vessel, at the side of the first receiving roller, is close to or in contact with the moving-upward outer surface of the tube shaped body of the first receiving roller. It is also desirable that the upper edge of the vessel wall of the second liquid pooling vessel is at a position higher than the upper edge of the vessel wall of the first pooling vessel.
It should be noted that, in the present invention, xe2x80x9cwheelchairxe2x80x9d includes an ambulance stretcher wheel.